JP2010242670A - Valve gear for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve gear for an internal combustion engine having a low-cost and highly accurate misfire detection means not requiring high-speed processing. <P>SOLUTION: An intake valve or an exhaust valve is driven with weak force from a fully closed position to a valve opening direction, thereby cylinder pressure different due to the presence or absence of misfire is determined according to the position of the valve. That is, the presence or absence of misfire is detected in such a manner that the movable portion position sensor 3 of the valve gear detects that the valve is driven from the fully closed position to the valve opening direction during the misfire and the valve is located in the fully closed position during normal combustion, the misfire detection means 16 temporarily reduces the electric conduction of the valve closing side-electromagnet of the valve, and it is detected whether the valve is fully closed according to information from the movable portion position sensor. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a valve operating apparatus for an electrically driven internal combustion engine, and detects misfire in order to prevent damage to a valve body or a mover.

  A configuration has been proposed in which an intake / exhaust valve of an internal combustion engine is electrically driven instead of the cam drive which is currently mainstream. When the intake / exhaust valve is configured to be electrically driven, a rotating mechanism such as a camshaft can be omitted, and the valve timing can be easily changed. The valve timing can be arbitrarily set, and the output characteristics and fuel consumption characteristics can be improved.

  As an electric drive device for an intake / exhaust valve, a configuration using an electromagnetic actuator using an electromagnet has been proposed (for example, see Patent Document 1). The actuator of this configuration has two springs, a spring that biases the mover (armature) in the valve opening direction and a spring that biases the mover in the valve closing direction. It has two electromagnets that attract in the valve opening direction and the valve closing direction.

  In this case, the movable part composed of the mover and the valve is held at a neutral position separated from the attraction surfaces of the two electromagnets by a predetermined position by the spring force of the two springs when no current flows through the electromagnet. In addition, when an electric current is applied to one of the electromagnets on the valve opening side or the valve closing side, the attraction force overcomes the spring force of the spring and is attracted to the electromagnet side by the electromagnetic attraction force generated at that time. .

  When the current of the electromagnet is interrupted in this state, the movable portion once passes through the neutral position by the spring force of the spring and approaches the other electromagnet. At this time, if a current is passed through the other electromagnet, the movable part is attracted to the other electromagnet.

  In this way, it is possible to displace the mover by a predetermined displacement width according to the energization / interruption operation of the currents of the two electromagnets, and using this displacement, the valve open state and valve close state can be changed. Switching.

  In such an electromagnetically driven intake / exhaust valve device, the exhaust valve operates in the valve opening direction in a situation where high-pressure combustion gas remains in the combustion chamber. For this reason, in order for the exhaust valve to operate in the valve opening direction, a larger amount of energy is required compared to the operation in the valve closing direction.

  For this reason, the neutral position of the mover is set to a position biased toward the electromagnet on the valve opening side. In this case, the repulsive force of the spring in the valve-closed state is larger than the repulsive force of the spring in the valve-opened state, and the valve-opening operation can be performed against the combustion pressure even if an electromagnet having the same characteristics as both electromagnets is used. it can.

  However, in the event of a misfire, the combustion pressure against the opening operation of the exhaust valve is greatly reduced. To reach the displacement end of the valve opening side electromagnet or the like. As a result, abnormal noise is generated and the mover is damaged.

  In order to solve this collision, in Patent Document 1, a misfire detection means is provided, and a speed control means is provided to reduce the speed of the mover when the exhaust valve is opened when a misfire is detected. And a valve operating device for an internal combustion engine that can prevent damage to the mover.

  In this prior art, as misfire detection means, in-cylinder pressure is measured to detect misfire, in-cylinder ion current after ignition plug discharge is measured to detect misfire, and misfire is detected based on crankshaft rotation fluctuation. Means have been proposed for detecting misfire based on the speed or acceleration of the valve body or mover when the exhaust valve is opened.

Japanese Patent No. 3702745

  The above-mentioned conventional misfire detection means has the following problems regarding cost and accuracy.

  In the case of means for measuring in-cylinder pressure and ion current and detecting misfire, an in-cylinder pressure sensor and an in-cylinder ion sensor which are not necessary for the valve operating apparatus are necessary, which causes a problem of cost increase.

  In the case of means for detecting misfire due to crank shaft rotation fluctuation, there is a problem that the detection accuracy is poor. This is because torque is generated by combustion and there is a delay before it appears as a change in the angular velocity of the crank angle. For this reason, the period during which the change in angular velocity appears is from the middle of the explosion stroke to the first half of the exhaust stroke, as shown in FIG. The specification for detecting misfire by rotational fluctuation is applied for OBD (On-Board Diagnostic System), but for OBD, it is set to include the above-mentioned period widely so that it can be detected accurately. . That is, the time of the start point and the end point of the rotation fluctuation detection period A in FIG. 10 is measured, converted to angular velocity, and the misfire and normal combustion are compared.

  However, the exhaust valve starts to be driven at the position of the open drive angle shown in FIG. 10 in the latter half of the explosion stroke. Since it is necessary to determine the presence or absence of misfire before starting to drive the exhaust valve, the determination cannot be made in time in the rotation fluctuation detection period A. For this reason, it is necessary to detect the angular velocity in a period such as the rotation fluctuation detection period B and determine the presence or absence of misfire. However, as apparent from FIG. 10, the period that can be set as the rotation fluctuation detection period B is short, and the misfire detection accuracy decreases accordingly.

  Thus, when misfire detection is performed due to rotational fluctuation, the detection accuracy is poor, and there are detection omissions or false detections. If there is even a detection failure even once, the mover will be damaged, and there is a risk that this internal combustion engine will become unusable. On the other hand, if an erroneous detection is made, the exhaust valve will not be opened sufficiently, resulting in a problem that desired engine performance cannot be obtained.

  In the case of means for detecting misfire based on the speed or acceleration calculated from the position sensor or speed sensor of the valve body or mover when the exhaust valve is opened, misfire detection should be performed when the exhaust valve is already opened. Therefore, it is necessary to perform deceleration processing simultaneously with detection of excessive speed. In other words, it is necessary to perform feedback control so that the target position and speed of the valve match the actual position and speed.

  For this reason, it is necessary for the microcomputer in the control device to read out signals from the position sensor and the speed sensor at a very short cycle to determine the occurrence of misfire. In addition, a short processing cycle means that only a very short time is allowed for processing timing errors. For example, in the case of 6000 rpm with a 4-cylinder engine, one stroke, that is, a 180 ° crank angle is a time of 5 ms. If the valve operating angle is the same as the valve operating angle of a general camshaft, it is assumed that the valve is driven from fully closed to fully open at a crank angle of 90 degrees, for example.

  In order to perform feedback control of this drive, it is considered that the processing needs to be performed at least 10 times. Then, when the feedback control cycle is 250 μs and the measurement cycle allowable error is 5%, the microcomputer is 12.5 μs or less. The control must be performed within the variation of. In order to realize this accuracy while performing other software processing, a high-speed microcomputer is required, that is, there is a problem of an increase in cost.

  The present invention has been made in view of the above-described points, and provides a valve operating apparatus for an internal combustion engine including a misfire detection means that is low in cost, accurate, and does not require high-speed processing.

  The valve operating apparatus for an internal combustion engine according to the present invention includes a mover that works in conjunction with an exhaust valve, a valve-opening electromagnet that operates the mover in the valve opening direction when energized, and the valve mover that operates in the valve closing direction when energized. A valve-closing electromagnet to be moved, a first elastic member for urging the mover in the valve opening direction, and a first elastic member for urging the mover in the valve closing direction and when both the electromagnets are not energized. A second elastic member that cooperates to hold the mover at a neutral position of both electromagnets, position detection means for detecting whether the mover is in a fully closed position, and misfire detection for detecting misfire of the internal combustion engine. And a speed control means for controlling speed so that the speed of the mover is reduced when the exhaust valve is opened when the misfire detection means detects misfire. The misfire detection means temporarily determines the energization amount of the valve closing side electromagnet of the exhaust valve. Small Toe, the information of the position detecting means, the exhaust valve is to detect whether fully closed, and detects whether or not the misfire.

  Also, a mover interlocking with each of the intake valve and the exhaust valve, a valve opening side electromagnet that operates the mover in the valve opening direction when energized, and a valve closing side electromagnet that operates the mover in the valve closing direction when energized A first elastic member that urges the mover in the valve opening direction, and urges the mover in the valve closing direction and cooperates with the first elastic member when the electromagnets are not energized. A second elastic member for holding the mover at a neutral position of both electromagnets; position detecting means for detecting whether the mover is in a fully closed position; misfire detecting means for detecting misfire of the internal combustion engine; and the misfire A valve operating apparatus for an internal combustion engine, comprising: a speed control means for controlling speed so that the speed of the mover is reduced when the exhaust valve is opened when the detection means detects a misfire, wherein the misfire detection means Temporarily reduces the energization amount of the closing side electromagnet of the intake valve. The information of the position detecting means, the intake valve by detecting whether fully closed, and detects whether or not the misfire.

  According to the present invention, it is possible to provide a misfire detection means that does not require an increase in cost, is accurate, and does not require high-speed processing by adding only the use of an existing sensor or a simple switch. As a detection means, by temporarily reducing the energization amount of the closing side electromagnet of the intake valve or exhaust valve, the difference in in-cylinder pressure due to the presence or absence of misfire is reflected in whether or not the valve is fully closed, and this is positioned It can be detected by the detection means to determine misfire.

1 is a system configuration diagram of a valve operating apparatus for an internal combustion engine in Embodiment 1 according to the present invention. FIG. In Embodiment 1 which concerns on this invention, it is a figure which compares the force to the valve by the presence or absence of misfire at the time of high load, and the force by electric current value Ichk. In Embodiment 1 which concerns on this invention, it is a figure which compares the force to the valve by the presence or absence of misfire at the time of low load, and the force by the electric current value Ichk. It is a control flowchart of the fully closed electromagnet by the misfire detection means and the speed control means in Embodiment 1 which concerns on this invention. 4 is a time chart when the exhaust valve is opened to detect misfire in the first embodiment according to the present invention. It is a block diagram which shows the drive method of the valve operating control process in Embodiment 1 which concerns on this invention. It is a control flowchart of the fully closed electromagnet by the misfire detection means and speed control means in Embodiment 2 which concerns on this invention. It is a time chart in the case of performing valve opening operation | movement of the intake valve for the misfire detection in Embodiment 2 which concerns on this invention. It is a block diagram which shows the drive method of the valve operating control process in Embodiment 2 which concerns on this invention. It is a figure explaining the problem in the case of misfire detection by a rotation fluctuation | variation in a prior art example.

Embodiment 1 FIG.
Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an overall configuration in which a valve operating apparatus for an internal combustion engine according to the present invention is applied to an internal combustion engine for a vehicle.

  As shown in FIG. 1, the cylinder head 52 fixed to the upper part of the cylinder 51 of the engine is provided with a valve 54 (only a single valve is shown in FIG. 1). A spring retainer 55 is fixed to the upper part of the valve shaft 61 extending upward from the valve 54, and a coil spring 56 that urges the valve 54 in the valve closing direction is provided between the spring retainer 55 and the cylinder head 52. ing. Reference numeral 53 denotes a combustion chamber.

  In addition, a housing 60 serving as a case for an electromagnetic valve is provided upright on the cylinder head 52. Inside the housing 60, the valve-closing electromagnet 11 and the valve-opening electromagnet 12 are fixed at positions facing each other vertically with a predetermined interval. Between the valve-closing electromagnet 11 and the valve-opening electromagnet 12, a soft magnetic movable element (hereinafter referred to as an armature) 57 is supported by a movable element shaft member 62 so as to be slidable up and down.

  A spring retainer 58 is fixed to the mover shaft member 62 at a position above the valve-closing electromagnet 11, and the armature 57 is biased in the valve opening direction between the ceiling inner surface of the housing 60 and the spring retainer 58. A coil spring 59 is provided.

  Further, on the ceiling of the housing 60, a movable part speed sensor 2 that detects the speed of the movable part (the armature 57 and the valve 54 are collectively referred to as a movable part) and outputs a speed signal, detects the position of the movable part, and a position signal. Is provided, and the velocity signal and the position signal are transmitted to the control device 1.

  The control device 1 includes an engine control processing unit 14 and a valve operating control processing unit 15. The engine control processing unit 14 provides information on the crank angle and the operating state of the internal combustion engine, for example, information on the engine speed and engine load. This is transmitted to the control processing unit 15. The valve control processing unit 15 includes a misfire detection unit 16 and a speed control unit 17, and uses a valve closing side electromagnet current control unit 9 and a valve opening side electromagnet current control unit to calculate the current target value calculated from the operating state of the internal combustion engine. 10 is output.

  The valve closing side electromagnet current control unit 9 and the valve opening side electromagnet current control unit 10 electromagnetically supply current from the power supply unit 13 to the electromagnets 11 and 12 by PWM control in accordance with the input current target values. The power can be controlled.

  Next, the operation of the valve gear according to the present embodiment will be described. The armature 57 is suspended from the coil springs 56 and 59, and when the valve-closing electromagnet 11 and the valve-opening electromagnet 12 are not energized, the approximate center position of the valve-closing electromagnet 11 and the valve-opening electromagnet 12, or The dimensions and spring constants of the coil springs 56 and 59 are set so as to be located at positions displaced from the valve opening side electromagnet.

  Here, the natural frequency fo of the spring-mass system composed of the coil springs 56 and 59 and the movable part including the valve 54 and the armature 57 is set such that the combined spring constant is K, the total inertia mass is m, and the friction is When ignored, it is known that fo = √ (K / m).

  In the initial operation before starting the engine, the valve-closing electromagnet 11 and the valve-opening electromagnet 12 are alternately energized at a period corresponding to the natural frequency fo. Then, by resonating the movable part, the amplitude of the movable part is gradually increased, and at the final stage of the initial operation, for example, the armature 57 is attracted to the valve-closing electromagnet 11 and this attracted state is maintained.

  Next, when the engine is started or normally operated, for example, when the valve is opened, first, the current of the valve-closing electromagnet 11 is turned off, and the movable portion starts to move downward by the combined spring force of the coil spring. Due to energy loss due to frictional force or the like, the armature 57 cannot be moved to the valve fully open position only by the combined spring force. Therefore, when the armature 57 is sufficiently close to the valve-opening electromagnet 12 and the valve-opening electromagnet 12 is energized at a position where the electromagnetic force is effective, the armature 57 is attracted to the valve-opening electromagnet 12 and the valve 54 is fully opened. It becomes.

  Now, when the exhaust valve is opened, the exhaust valve must be opened against the pressure of the combustion gas, so that the spring of the exhaust valve is reinforced compared to the intake valve. Further, the neutral position of the armature 57 that drives the exhaust valve is set to a position that is biased toward the valve opening side electromagnet rather than the center position between the valve opening side electromagnet 12 and the valve closing side electromagnet 11.

  For this reason, when the internal combustion engine misfires, the pressure of the combustion gas does not act on the exhaust valve, so that the speed of the armature 57 at the time of valve opening increases too much and collides with the valve opening side displacement end at a high speed, generating noise. Or the armature 57 is damaged. In order to prevent this, a misfire detection means 16 for determining the presence or absence of misfire for each cylinder and a speed control means 17 for decelerating the speed of the armature 57 in the case of misfire are provided in the valve control control section 15. .

  The detection principle of the misfire detection means 16 will be described with reference to FIG. FIG. 2 shows the in-cylinder pressure force acting on the valve 54 with the crank angle on the horizontal axis. The two curves show the change in force during normal combustion and misfire.

  If the air-fuel mixture is compressed in the compression stroke, for example, if it is ignited at the compression top dead center, the in-cylinder pressure rapidly rises due to explosion, and the in-cylinder pressure decreases while pushing down the piston. If the opening drive angle at which the valve 54 starts to be opened is, for example, 160 degrees after the compression top dead center (ATDC), the valve opens at that angle and the in-cylinder pressure decreases. On the other hand, in the case of misfire, since there is no explosion, the in-cylinder pressure decreases at the peak at the compression top dead center, and the valve 54 opens at the open drive angle, so the in-cylinder pressure decreases. Note that the open drive angle is usually set before ATDC 180 degrees, and since this patent does not propose a new technique for this angle, the open drive angle before applying the technique of this patent may be used.

  A force acts on the valve 54 in the fully closed position in a direction to close the armature 57 due to the in-cylinder pressure, and a force acts in a direction to open the armature 57 due to the combined spring force. In addition, an attractive force acts in a direction to close the armature 57 in accordance with the current of the valve-closing electromagnet 11. Depending on whether the resultant force is the valve closing direction or the valve opening direction, whether the valve 54 in the fully closed position remains in the fully closed position or moves to the open side is determined. That is, a comparison is made between the combined force acting in the valve opening direction obtained by subtracting the combined spring force from the suction force generated by the current value Ichk and the force acting in the valve closing direction due to the in-cylinder pressure. Whether or not to move is determined.

  Therefore, if the combined force acting in the valve opening direction is set in the region of the difference in in-cylinder pressure between normal combustion and misfire, that is, the difference in force acting in the valve closing direction, the presence or absence of misfire can be determined. become. That is, the presence / absence of misfire can be determined by applying the combined force acting in the valve opening direction determined by the current value Ichk in the section from the misfire determination start angle to the misfire determination end angle shown by the determination line in FIG. The above is the detection principle of the misfire detection means 16.

  For this reason, the misfire determination start angle, the misfire determination end angle, and the current value Ichk that define the determination line are set as follows. First, several operating states of the internal combustion engine, for example, engine speed, engine load, and ignition timing are set, normal combustion and misfire are generated, and changes in the in-cylinder pressure are measured. The time when the in-cylinder pressure difference is large is set as the misfire determination start angle and the misfire determination end angle. For example, the misfire determination start angle is 10 crank angles after ignition, and the misfire determination end angle is 70 crank angles after ignition. Further, it may be a function such as a crank angle or an operating state of the internal combustion engine. However, the time of this section is set to a time that allows the armature 57 to be fully opened if a misfire has occurred. Further, since the misfire determination start angle and the misfire determination end angle mutually affect the next current value Ichk, it is not possible to determine only these first, and it is necessary to set them together with the current value Ichk.

  Next, the in-cylinder pressure difference is converted into a force difference according to the valve area or the like. In the section defined above, the current value Ichk is set so that the resultant force acting in the valve opening direction obtained by subtracting the resultant spring force from the suction force generated by the current value Ichk is in the middle of the force difference region. To do. Alternatively, several current values Ichk are set, actual combustion and misfire are actually generated, and the current value Ichk is adapted by actually measuring whether or not the valve is opened. Moreover, although it is a fixed value in FIG. 2, it can also be set in a curve according to the crank angle. Moreover, it is good also as functions, such as the driving | running state of an internal combustion engine.

  When the difference in the in-cylinder pressure after ignition is small, such as when the engine load is low, for example, in the case shown in FIG. 3, the region of the in-cylinder pressure difference between normal combustion and misfire becomes narrow. In such a case, the boundary between the determination line and the difference area is close, and there is a possibility of detection omission or erroneous determination. However, a small difference in in-cylinder pressure after ignition means that the difference in in-cylinder pressure at the open drive angle is smaller. Since the difference in the in-cylinder pressure at the open drive angle is small, the acceleration of the armature 57 is substantially the same during normal combustion and during misfiring, and speed control is not necessary.

  That is, even if there is a detection omission or an erroneous determination in such a case, the armature 57 does not collide with the displacement end of the valve-opening electromagnet or the like, so that no abnormal noise or damage to the armature 57 occurs. On the other hand, the cause of the problem of misfire detection due to rotational fluctuation in the prior art is that the section for detecting rotational fluctuation is shortened. For this reason, even when the difference in the cylinder internal pressure is large, there is a high possibility of detection omission or erroneous determination, and there is a risk that abnormal noise or damage to the armature 57 may occur.

  Hereinafter, the description returns to the operation of the embodiment. The misfire detection means 16 temporarily closes the intake valve or the exhaust valve on the valve closing side at the misfire determination start angle calculated according to the crank angle or the operating state of the internal combustion engine transmitted from the engine control processing unit 14. The target current value of the electromagnet is lowered to the current value Ichk. Then, the attractive force of the valve-closing electromagnet 11 is weakened, and the combined spring force becomes dominant, and as a result, the movable part tends to move in the valve opening direction. At this time, if there is no misfire, the in-cylinder pressure is high due to the combustion gas, so the valve does not move from the fully closed position. If there is a misfire, the in-cylinder pressure is low and the valve starts to move in the valve opening direction from the fully closed position.

  Whether the valve has moved in the valve opening direction from the fully closed position, while the target current value is being decreased, or at the misfire determination end angle, the movable part position sensor 3 or the movable part speed sensor 2, Alternatively, in the case of a valve gear without these sensors, it is detected by a switch that detects whether or not the valve is in the fully closed position, and it is determined whether or not a misfire has occurred. If the movable part position sensor 3 and the movable part speed sensor 2 are not provided, a switch is added to detect misfire, but it is less expensive than an in-cylinder pressure sensor or the like. That is, unlike the conventional example, an expensive sensor is not required.

  At the misfire determination end angle calculated according to the crank angle and the operating state of the internal combustion engine, the target current value of the valve-closing electromagnet is returned to the original holding current value Ihld. Since the period during which the current value Ichk is decreased may be set within a period in which the in-cylinder pressure during normal combustion and during misfire is different, the allowable error in execution timing is not as severe as in the conventional example. For example, in the case of 6000 revolutions in a 4-cylinder engine, the time when the in-cylinder pressure difference between the normal combustion and the misfire is large is about one stroke period, that is, 5 ms, and the target current value change process is performed twice in that period. Just do it. As the allowable variation of each execution timing, if the crank angle is 10 degrees, this is about 280 μs in time, and even if this processing is waited while the microcomputer performs other software processing, the allowable range No problem. That is, a microcomputer having a lower speed than the conventional example may be used.

  As described above, after the misfire determination means 16 finishes determining whether or not misfire has occurred, the valve 54 is opened at the open drive angle, but if the misfire has not occurred, the valve-closing electromagnet 11 is stopped and misfired. If so, the speed control means 17 decelerates the valve. Since this patent does not propose a new technique for the speed control means 17, the speed control means provided in the valve gear prior to the application of the technique of this patent may be used as it is. Alternatively, as described below, the valve-closing electromagnet 11 may be driven with a predetermined current value Imf from the opening drive angle to the deceleration period end angle, and then the energization may be stopped. In addition, the value adapted beforehand is used for the deceleration period end angle and the current value Imf. These values may be updated as needed according to the crank angle and the operating state of the internal combustion engine. For example, the deceleration period end angle is assumed to be ATDC 170 degrees. The current Imf is set to a value suitable for the same valve speed as that during normal combustion.

  Next, the operation of the present embodiment will be described with reference to the flowchart of FIG.

  FIG. 4 is a flowchart showing the processing of the misfire detection means 16 and the speed control means 17. The valve control processing unit 15 in the control device 1 starts from a predetermined period, a certain time, or every certain crank angle calculated according to the crank angle and the operating state of the internal combustion engine, or when the following determination angle is reached. Start processing. For example, it is performed for every 10 degrees crank angle until the exhaust stroke ends, and the timing is determined by the value of the crank angle after compression top dead center (ATDC). Alternatively, the process is started at the misfire determination start angle, the misfire determination end angle, the open drive angle, and the deceleration period end angle.

  First, in step 10 (hereinafter, step is abbreviated as S), it is determined whether or not the misfire determination start angle is reached. When the misfire determination start angle is not reached, Y determination is made, and the target current value of the valve-closing electromagnet 11 is set to the current value Ihdl for holding the armature 57 in the fully closed position. Next, in S12, the misfire flag is set to 0 (cleared), and the process ends at the end.

  In S10, the misfire determination start angle is reached, and in S13, the misfire determination end angle is not reached. That is, the process proceeds to S14 from the misfire determination start angle to the misfire determination end angle, and the valve-closing electromagnet 11 is reached. The target current value is set to the current value Ichk for detecting whether or not the misfire has occurred.

  Next, in S15, it is determined from the information of the position detection means whether or not the armature 57 is in the fully closed position. If it is the fully closed position, the determination is Y, and the process ends at the end. If it is not the fully closed position, the determination is N, and in S16, the misfire flag is set (set) to 1, and the process ends at the end.

  When the position detection means is the movable part position sensor 3, the determination is made based on whether or not the detection position is a fully closed position. When the position detecting means is the movable part speed sensor 2, it is determined whether or not the armature 57 is in the fully closed position based on whether or not the speed is generated in the valve opening direction. When the valve operating apparatus does not have the movable part position sensor 3 or the movable part speed sensor 2, a switch that is turned on only when the armature 57 is in the fully closed position is provided, and the determination is made by turning this switch on / off.

  In S13, the misfire determination end angle is reached, and in S17, the open drive angle is not reached. That is, the process proceeds to S18 between the misfire determination end angle and the open drive angle, and the target current of the valve-closing electromagnet is reached. The value is set again to the current value Ihdl for holding the armature 57 in the fully closed position. Then, the process ends at the end.

  In S17, the open drive angle is reached, and in S19, the deceleration period end angle has not been reached. That is, during the period from the open drive angle to the deceleration period end angle, the process proceeds to S20, and the misfire flag is 0 (clear). It is determined whether or not. If the misfire flag is 0 (clear), the determination is Y, and the target current value of the valve-closing electromagnet 11 is set to 0 in S21. If the misfire flag is 1 (set) in S20, the determination is N, and the target current value of the valve-closing electromagnet 11 is set to the current value Imf for decelerating the armature 57 in S22. In both S21 and S22, the process proceeds to the end, and the process ends.

  In S19, the deceleration period end angle is reached, that is, after the deceleration period end angle, the process proceeds to S23, the target current value of the valve-closing electromagnet 11 is set to 0, and the process ends at the end. Above, the process with respect to the target electric current value of the valve closing side electromagnet 11 is complete | finished. Thereafter, at a predetermined timing, the target current value of the valve-opening electromagnet 12 is set to the current value Ihdl. As a result, the armature 57 is held in the fully open position.

  FIG. 5 is a time chart when the target current value of the valve closing side electromagnet 11 of the exhaust valve is temporarily reduced to the current value Ichk in the misfire detection means 16 and the speed control means 17 of the embodiment. From the top of the figure, the exhaust valve position, the valve closing side electromagnet current, the valve opening side electromagnet current, and the time changes of each are shown. In addition, the valve closing side electromagnet current, the valve opening side electromagnet current, and the current values for holding the respective valves are set to the same Ihld for the sake of simplicity.

  When the misfire determination start angle is not reached, the target current value of the valve-closing electromagnet 11 is set to the current value Ihdl. At this time, the armature 57 is held in the fully closed position.

  Between the misfire determination start angle and the misfire determination end angle, the target current value of the valve-closing electromagnet 11 is set to the current value Ichk. During this period or at the end of this period, the presence or absence of misfire is determined from the information of the position detection means. The time from the misfire determination start angle to the misfire determination end angle is set to a time that allows the armature 57 to be fully opened in the case of misfire.

  Between the misfire determination end angle and the opening drive angle, the target current value of the valve-closing electromagnet 11 is set again to the current value Ihdl. The time from the misfire determination end angle to the opening drive angle is set to the time for the armature 57 to return to the fully closed position when a misfire has occurred. Alternatively, this time can be set to 0, but in the case of a misfire, the target current value and execution time of the next speed control means are determined according to the position and speed of the exhaust valve that has started moving for determination. Need to change.

  From the opening drive angle to the deceleration period end angle, the target current value of the valve-closing electromagnet 11 is set to 0 or the current value Imf according to the presence or absence of the misfire detected earlier. As the opening drive angle, the deceleration period end angle, and the current value Imf, values calculated according to the crank angle and the operating state of the internal combustion engine are used.

  After the deceleration period end angle, the target current value of the valve-closing electromagnet 11 is set to 0 even if misfire occurs. Thereafter, the target current value of the valve-opening side electromagnet 12 is set to the current value Ihdl. As a result, the armature 57 is held in the fully open position. With respect to this angle, this patent does not propose a new technology, so the angle before applying the technology of this patent may be kept.

  FIG. 6 is a block diagram showing details of the control device 1 in the present embodiment. In the figure, a valve control processing unit 15 outputs a speed target value generation unit 5 that generates a speed target value of the movable part based on a position signal output by the movable part position sensor 3 and a movable part speed sensor 2 outputs. The comparison unit 4 that compares the speed signal with the speed target value, and the current target value generation unit that generates a current target value to be supplied to the valve closing side electromagnet 11 or the valve opening side electromagnet 12 according to the comparison result of the comparison unit 4 6 and a switch 7 for switching whether the current target value is supplied to the valve-closing electromagnet current control unit 9 or the valve-opening electromagnet current control unit 10. The engine control processing 15, the valve closing side electromagnet current control unit 9, the valve opening side electromagnet current control unit 10, the valve closing side electromagnet 11, and the valve opening side electromagnet 12 are the same components as those described in FIG.

Embodiment 2. FIG.
Although Embodiment 1 is a case where an exhaust valve is used for misfire detection, a case where an intake valve is used for misfire detection will be described below. One cylinder is provided with an intake valve and an exhaust valve, and these valve operating devices have the same configuration as that shown in FIG. In order to clarify which valve is configured, each name is supplemented and distinguished from an intake valve or an exhaust valve.

  The operation of the valve operating apparatus is the same as that of the first embodiment except that the misfire detection means changes the valve to be temporarily driven to the intake valve. As in the description of FIG. 5, the current value for holding the valve is set to the same Ihld for all the electromagnet currents for the sake of simplicity.

  FIG. 7 is a flowchart showing the processing of the misfire detection means 16 and the speed control means 17. The valve control processing unit 15 in the control device 1 starts from a predetermined period, a certain time, or every certain crank angle calculated according to the crank angle and the operating state of the internal combustion engine, or when the following determination angle is reached. Start processing. For example, it is performed for every 10 degrees crank angle until the exhaust stroke ends, and the timing is determined by the value of the crank angle after compression top dead center (ATDC). Alternatively, the process is started at the misfire determination start angle, the misfire determination end angle, the open drive angle, and the deceleration period end angle.

  First, in S30, it is determined whether it is a misfire determination start angle. When the misfire determination start angle is not reached, Y determination is made, and the target current value of the intake valve closing side electromagnet 11 is set to the current value Ihdl for holding the intake valve armature 57 in the fully closed position. Next, in S32, the misfire flag is set to 0 (cleared), and the process ends at the end.

  In S30, the misfire determination start angle is reached. In S13, the misfire determination end angle is not reached. That is, the process proceeds to S34 from the misfire determination start angle to the misfire determination end angle, and the intake valve is closed. The target current value of the side electromagnet 11 is set to a current value Ichk for detecting whether or not a misfire has occurred.

  Next, in S35, it is determined from the information of the position detection means whether or not the intake valve side armature 57 is in the fully closed position. If it is the fully closed position, the determination is Y, and the process ends at the end. If it is not the fully closed position, the determination is N, and in S36, the misfire flag is set (set) to 1, and the process ends at the end.

  When the position detection means is the movable valve position sensor 3 of the intake valve, the determination is made based on whether or not the detection position is a fully closed position. When the position detecting means is the moving part speed sensor 2 of the intake valve, it is determined whether or not the armature 57 of the intake valve is in the fully closed position depending on whether or not the speed is generated in the valve opening direction. If the valve operating device does not have the intake valve movable part position sensor 3 or the intake valve movable part speed sensor 2, a switch that is turned on only when the intake valve armature 57 is in the fully closed position is provided. Determine by / OFF.

  In S33, the misfire determination end angle is reached, and in S37, the open drive angle is not reached. That is, the process proceeds to S38 between the misfire determination end angle and the open drive angle, and the valve closing side electromagnet of the intake valve The target current value of 11 is set again to the current value Ihdl for holding the armature 57 of the intake valve in the fully closed position. Then, the process ends at the end. Thus, the processing for the target current value of the valve closing side electromagnet 11 of the intake valve is completed.

  In S37, the opening drive angle is reached, and in S39, the deceleration period end angle has not been reached. That is, the process proceeds to S40 between the opening drive angle and the deceleration period end angle, and the misfire flag is 0 (clear). It is determined whether or not. If the misfire flag is 0 (clear), the determination is Y, and the target current value of the valve closing side electromagnet 11 of the exhaust valve is set to 0 in S41. If the misfire flag is 1 (set) in S40, the determination is N, and in S42, the target current value of the exhaust valve closing-side electromagnet 11 is set to the current value Imf for decelerating the exhaust valve armature 57. Set. In both S41 and S42, the process proceeds to the end, and the process ends.

  In S39, the deceleration period end angle is reached, that is, after the deceleration period end angle, the process proceeds to S43, the target current value of the valve closing side electromagnet 11 of the exhaust valve is set to 0, and the process ends at the end. This completes the processing for the target current value of the valve closing side electromagnet 11 of the exhaust valve. Thereafter, at a predetermined timing, the target current value of the electromagnet on the valve opening side of the exhaust valve is set to the current value Ihdl. As a result, the armature 57 of the exhaust valve is held in the fully open position.

  FIG. 8 is a time chart when the target current value of the valve closing side electromagnet 11 of the intake valve is temporarily reduced to the current value Ichk in the misfire detection means 16 and the speed control means 17 of the embodiment. From the top of the figure, intake valve position, exhaust valve position, intake valve closing electromagnet current, intake valve opening electromagnet current, exhaust valve closing electromagnet current, exhaust valve opening electromagnet current, respectively The time change of is shown.

  When the misfire determination start angle is not reached, the target current value of the valve closing side electromagnet of the intake valve is set to the current value Ihdl. At this time, the armature 57 of the intake valve is held in the fully closed position.

  Between the misfire determination start angle and the misfire determination end angle, the target current value of the valve closing side electromagnet of the intake valve is set to the current value Ichk. Similar to FIG. 5, during this period or at the end of this period, the presence or absence of misfire is determined from the information of the position detection means. The time from the misfire determination start angle to the misfire determination end angle is set to a time that allows the armature 57 to be fully opened in the case of misfire.

  After the misfire determination end angle, the target current value of the valve closing side electromagnet of the intake valve is set again to the current value Ihdl.

  Between the opening drive angle and the deceleration period end angle, the target current value of the valve closing side electromagnet of the exhaust valve is set to 0 or the current value Imf according to the presence or absence of the misfire detected previously.

  After the deceleration period end angle, even if a misfire occurs, the target current value of the electromagnet on the valve closing side of the exhaust valve is set to 0, and the value is used to hold the armature 57 in the fully open position. Thereafter, the target current value of the valve opening side electromagnet of the exhaust valve is set to the current value Ihdl. As a result, the armature 57 is held in the fully open position. With respect to this angle, this patent does not propose a new technology, so the angle before applying the technology of this patent may be kept.

  FIG. 9 is a block diagram showing details of the control device 1. In contrast to FIG. 6 of the first embodiment, the valve closing side electromagnet current control unit 9 and the valve opening side electromagnet current control unit 10 are provided in the respective valves. In addition, the component numbers on the exhaust side are marked with b. Since other components and operations are the same, description thereof is omitted.

  Thus, when misfire detection is performed using the intake valve, the time from the misfire determination end angle to the open drive angle can be shortened compared to when the exhaust valve is used for misfire detection. This is because there is a slight delay time from when the target current value of the valve closing side electromagnet of the exhaust valve is set to 0 to when the exhaust valve is driven in the opening direction. Even if this time is shortened, the exhaust valve is opened after the armature 57 of the intake valve returns to the fully closed position, that is, the intake valve and the exhaust valve are not opened simultaneously. As a result, the required time from the misfire determination start angle to the deceleration period end angle can be shortened, and for example, application at higher engine speeds is also possible.

  In the first and second embodiments, the processing timing of the misfire detection means and the speed control means is determined by the value of the crank angle, but the angular deviation or the timing based on the ignition timing, the timing for driving in the valve opening direction, etc. It is also possible to define by time deviation. In this case as well, values calculated according to the crank angle and the operating state of the internal combustion engine are used.

  In the first and second embodiments, the engine control process and the valve operating control process are configured in one control device. However, as in the conventional example, separate devices, that is, the engine control device, It can also be divided into control devices for valve control. According to this patent, since the load on the microcomputer necessary for detection of misfire is reduced, the engine control process and the valve operating control process can be configured in one control device, and the process can be performed by one microcomputer. There is a significant cost reduction.

  Further, in the first and second embodiments, the presence or absence of misfire determined by the misfire detection means is used only for speed control of the valve gear, but may be used for other controls such as compliance with OBD regulations. That is, in the case of an engine equipped with a valve operating device, if there is a sensor required for misfire detection corresponding to the OBD regulations, it can be deleted, and the cost can be reduced.

  DESCRIPTION OF SYMBOLS 1 Control apparatus, 2 Movable part speed sensor, 3 Movable part position sensor, 9 Valve closing side electromagnet current control part, 10 Valve opening side electromagnet current control part, 11 Valve closing side electromagnet, 12 Valve opening side electromagnet, 14 Engine control process Unit, 15 valve control control unit, 16 misfire detection means, 17 speed control means.

Claims (6)

A mover linked to the exhaust valve;
A valve-opening electromagnet that operates the mover in the valve-opening direction when energized;
A valve-closing electromagnet that operates the mover in the valve-closing direction when energized;
A first elastic member for urging the mover in the valve opening direction;
A second elastic member that urges the mover in the valve closing direction and holds the mover in a neutral position in cooperation with the first elastic member when the electromagnets are not energized;
Position detecting means for detecting whether or not the mover is in a fully closed position;
Misfire detection means for detecting misfire of the internal combustion engine;
A valve operating device for an internal combustion engine comprising speed control means for controlling speed so that the speed of the mover is reduced when the exhaust valve is opened when the misfire detection means detects misfire;
The misfire detection means temporarily reduces the energization amount of the electromagnet on the valve closing side of the exhaust valve, and detects whether or not a misfire has occurred by detecting whether the exhaust valve is fully closed based on the information of the position detection means. A valve operating apparatus for an internal combustion engine characterized by detecting the above. A mover linked to each of the intake and exhaust valves;
A valve-opening electromagnet that operates the mover in the valve-opening direction when energized;
A valve-closing electromagnet that operates the mover in the valve-closing direction when energized;
A first elastic member for urging the mover in the valve opening direction;
A second elastic member that urges the mover in the valve closing direction and holds the mover in a neutral position in cooperation with the first elastic member when the electromagnets are not energized;
Position detecting means for detecting whether or not the mover is in a fully closed position;
Misfire detection means for detecting misfire of the internal combustion engine;
A valve operating device for an internal combustion engine comprising speed control means for controlling speed so that the speed of the mover is reduced when the exhaust valve is opened when the misfire detection means detects misfire;
The misfire detection means temporarily decreases the energization amount of the closing side electromagnet of the intake valve, and detects whether the intake valve is fully closed by detecting whether the intake valve is fully closed based on the information of the position detection means. A valve operating apparatus for an internal combustion engine characterized by detecting the above. The valve operating apparatus for an internal combustion engine according to claim 1 or 2,
The valve operating device for an internal combustion engine, wherein the position detecting means is any one of a mover position sensor, a mover speed sensor, and a switch for detecting whether or not the mover is fully closed. The valve operating apparatus for an internal combustion engine according to any one of claims 1 to 3,
In the misfire detection means, when the energization amount of the valve-closing electromagnet is temporarily reduced, the energization amount is determined in the valve closing direction by the attractive force exerted on the mover by the valve-closing electromagnet and the in-cylinder pressure at the time of misfire. The combined force does not exceed the combined force in the valve opening direction by the first and second elastic members, and the valve closing direction by the attractive force exerted on the mover by the valve-closing electromagnet and the in-cylinder pressure during normal combustion The composite valve operating device for an internal combustion engine is characterized in that the combined force exceeds a combined force in the valve opening direction by the first and second elastic members. The valve operating apparatus for an internal combustion engine according to any one of claims 1 to 4,
An engine control processing unit for transmitting crank angle and internal combustion engine operation information to the misfire detection means;
In the misfire detection means, the start timing and end timing for temporarily reducing the energization amount of the valve-closing electromagnet are the start timing when the predetermined time has elapsed from ignition, when the predetermined crank angle has elapsed from ignition, or predetermined When the crank angle has been reached, the end timing is when a predetermined time has elapsed since the energization amount was decreased, when the predetermined crank angle has elapsed since the decrease in the energization amount, when the predetermined crank angle has been reached, and when to drive in the valve opening direction A valve operating apparatus for an internal combustion engine characterized by being either a predetermined time before or a predetermined crank angle before timing for driving in the valve opening direction. The valve operating apparatus for an internal combustion engine according to claim 5,
In the misfire detection means, the start timing, end timing, and energization amount for temporarily decreasing the energization amount of the valve-closing electromagnet are calculated according to the crank angle from the engine control processing unit and the operating state of the internal combustion engine. A valve operating apparatus for an internal combustion engine.

Images